Where,mystartup.sh: Your startup script namedefaults : The argument 'defaults' refers to the default runlevels, which are 2 through 5.100 : Number 100 means script will get executed before any script containing number 101. Just run the command ls –l /etc/rc3.d/ and you will see all script soft linked to /etc/init.d with numbers.

Next time you reboot the system, you custom command or script will get executed via mystartup.sh. You can add more commands to this file or even call other shell/perl scripts from this file too.

> just want to ask…when you use the rc.local, where does the programs or scrits have to be located? You have to specify the full path of command or script; you can put them into your own directory or into /etc/init.d directory. This script will be executed *after* all the other init scripts. You can put your own initialization stuff in here if you don’t want to do the full Sys V style init stuff.